The present invention relates to an installation/removal device for installing and/or removing a fuel injector, especially a high-pressure, direct-injection valve, in/from a receiving bore hole of an internal-combustion-engine cylinder head. The high-pressure, direct-injection valve injects fuel directly into the combustion chamber of the internal combustion engine.
A removal device for removing a direct-injection injector is described, for example, in German published Patent Application No. 197 05 990. The removal device has a sheathing member, which at least partially surrounds the fuel injector and must already be inserted into the receiving bore hole, together with the fuel injector, during assembly. At a first end of the sleeve member, a first collar section is provided, which can be frictionally connected to a fuel-injector receiving section that receives the first collar section. A second collar section offering a working surface for a tool is located at a second end of the sheathing member opposite to the first end. A disadvantage of this removal device is that the connection of the removal device to the fuel injector is not optimized, and the introduction of force by the tool acting on the removal device can be improved. Another disadvantage is that the removal device must already be attached to the fuel injector prior to installation and cannot just be attached subsequently, e.g., when servicing or replacing. Furthermore, the tool can only be used for removing the fuel injector and not for installing it.
A removal device for a diesel injection nozzle is described in U.S. Pat. No. 4,561,159. A fuel-injector end area opposite to the spray-discharge opening can be inserted into a slit of the removal device. In this case, the removal device is not inserted into the receiving bore hole of the cylinder head, and in the installed state, it does not remain in the receiving bore hole. The removal device described in U.S. Pat. No. 4,561,159 is rather a tool extension, which is fastened to the fuel injector prior to removing the fuel injector. However, the connection of the removal device to the fuel injector is relatively complicated. In addition, this tool can also only be used for removal purposes.
The installation/removal device according to the present invention has the advantage of being easily mountable on the fuel injector and being removable again, which allows the fuel injector to be easily installed and removed at the cylinder head of the internal combustion engine. This considerably simplifies maintenance work done on the fuel injector. The installation/removal device according to the present invention includes a sheathing member having a tubular section and a contacting section; the contacting section acting on the fuel injector by means of a contact area extending radially inward, and being adjustable between an engaged position, in which a frictional connection to the fuel injector can be established, and a released position, in which the installation/removal device can be removed from the fuel injector.
Advantageous further refinements and improvements of the installation/removal device are also possible.
The contacting section can be formed by at least two elastic, contacting subsections, which are separated from each other by cut-outs and can be deformed in a radial direction, using an adjusting mechanism. Thus, it is possible to adjust between the engaged position and released position in an especially simple manner.
The adjusting mechanism can include an inner section, which can be inserted into the sheathing member, can rotate with respect to it, and has a cam section acting on the elastic contacting subsections. The radial position of the contacting-subsection ends that act on a groove of the fuel injector is changed as a function of the turning position of the cam section. This design facilitates handling and allows a sturdy construction of the installation/removal device.
The inner section is advantageously provided with bore holes, and the sheathing member is provided with oblong openings formed in the axial direction in the same position as these bore holes, in order to attach a tool, such as a pin. The pin allows a large force to be exerted on the inner section. In addition, this facilitates the operation of the installation/removal device, especially in areas in the engine compartment that are difficult to access.
Alternatively, the adjusting mechanism may have a two-piece construction including a gripping part, which is attachable to the sheathing member and can rotate with respect to it, and a cam section, which can be detachably joined to the gripping part. Since the gripping part is mounted on the sheathing member of the installation/removal device, it is directly accessible. Therefore, it is not necessary to have an oblong opening in the sheathing member, which could decrease the rigidity of the tool. The gripping part is preferably provided with bore holes for attaching a tool, such as a pin.
The installation/removal device preferably has plugs disposed on the front end of the contacting sections, in order to axially support the installation/removal device at the valve housing during installation. These plugs allow compressive forces to be exerted by the installation/removal device on the fuel injector and thus enable the injector to be mounted securely.
In addition, the installation/removal device may have inclined deflectors attached to the inside of the contacting subsections, in order to provide support at the corresponding guide surfaces on the outside of the fuel injector. To attach the installation/removal device for the purpose of removing a fuel injector, it is therefore not necessary to operate the adjusting mechanism for adjusting the contacting section. The sliding of the gliding surfaces along the corresponding guide surfaces on the fuel injector allows the front ends of the contacting sections to reach the groove formed on the fuel injector, and to snap into place, by means of the inwardly jutting contact area.
The installation/removal device may be manufactured from sheet metal by rolling. However, it is also possible to manufacture the installation/removal device or parts thereof from a plastic reinforced with fiber glass, e.g., using an injection molding process.